/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/VoiceInterfaceImpl.h
Mutes a remote talker for the specified local player. NOTE: This only mutes them in the game unless the bIsSystemWide flag is true, which attempts to mute them globally
true if the function succeeds, false otherwise
virtual bool MuteRemoteTalker ( uint8 LocalUserNum, const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & PlayerId, bool bIsSystemWide )